1. Field of the Invention
The present invention relates to a microfluidic biochip, and more particularly, to a microfluidic biochip which integrates microfluidic device components with a special design.
2. Description of the Related Art
In recent years, severe infectious diseases, such as SARS (severe acute respiratory syndrome), have caused devastation and death throughout the world; as a result, concerns over rapid diagnosis of diseases have been raised. In the past, researchers had to practice complicated processes to obtaining biochemical test results. Thanks to the development of the ELISA (enzyme-linked immunosorbent assay) serological tests, there was a remarkable breakthrough in immediate diagnosis of an infectious disease; since then, it has been able to obtain biochemical test results relating to diagnosis of a disease within a few days. ELISA serological tests are used to detect antigen-antibody reactions in a serum sample mainly by detecting two kinds of immunoglobulins: immunoglobulin G (IgG) and immunoglobulin M (IgM). Generally, the presence of IgM in a great number is often detected at the early stage of infection, and IgG is present at the later stage, serving as a sign of past infection.
So far, the ELISA is the most common method used in the diagnosis of some virus-related infections. This assay method is based on the specificity in antigen-antibody reactions. In brief, an enzyme is linked to an antigen or antibody to form a bound complex and the bound complex will then bond to a specific antibody or antigen to become a detectable complex. Nonetheless, the whole operation process of an ELISA is labor-intensive and time-consuming. Moreover, the detection of the signs of infection, such as IgM and IgG, requires separate operation processes using an ELISA; IgM and IgG detection results cannot be obtained simultaneously. If more signs of disease activity are required through ELISA tests, it will need to consume a lot more clinical samples to be used in separate operation processes. Furthermore, manual operations tend to increase instabilities during an assay and reduce reliabilities of the acquired data.
There is no exact definition or classification with respect to a biochip. Generally, a biochip is a miniaturized instrument arranged on a substrate, which may be formed by a silicon chip, glass or a polymeric material for example, and utilizes miniaturization technology to integrate techniques in the fields of micro-electro-mechanical system (MEMS), optoelectronics, chemistry, biochemistry, medical engineering, and molecular biology technologies, etc., in order to perform tests for purposes associated with medical examination, environmental analysis, food testing and analysis, development of a new medicine, fundamental research, military defense, chemical synthesis, and so on. Biochips now available on the market are typically classified into three groups: gene chip, protein chip, and lab-on-a-chip. A so-called lab-on-a-chip may be designed according to different needs in order to have various reactions performed on a microchip. It's well known that biochemical reactions which can be performed on a lab-on-a-chip device include polymerase chain reactions (PCRs), DNA sequencing reactions, microfluidic operations, electrophoreses, mass spectrometries (MSs), antigen-antibody reactions, and common enzyme reactions.
A microfluidic biochip that is fabricated using MEMS technologies provides several advantages. It can achieve high examination efficacy, consumes few clinical samples and low energy, is compact in size and requires low fabrication cost. In particular, a microfluidic biochip that is designed to integrate microfluidic systems and detection device on a biochip has a great commercial potential and market value: complicated and expensive assay equipments can be replaced by a single, compact biochip to perform the entire assay functions.
Accordingly, an object of the present invention is to provide a microfluidic biochip having a special design to integrate microfluidic device components, so that rapid detections of complicated clinical samples can be performed on the biochip.